Structural Pattern Analysis in Patella vulgata Shells Using Raman Imaging

Patella vulgata shells preserve geochemical and structural variations that can provide insights into past environmental conditions. Their composition, primarily calcium carbonate with organic residues from the biomineralization process, is influenced by external factors, such as sea surface temperature. Raman spectroscopy has emerged as a rapid, non-destructive tool for studying biogenic carbonates, enabling the identification of crystalline phases, organic components, and ion distribution. In this study, Raman imaging was applied to six shell sections of P. vulgata live-collected from Langre Beach in Cantabria, Spain. Spectral data were acquired using a Raman probe with a 532 nm excitation laser, providing high-resolution mapping of structural and compositional features. The analysis revealed spatial variations in mineralogy, organic matrix distribution, and ion incorporation in the calcium carbonate lattice, suggesting patterns originating during shell formation. Notably, the results suggest a consistent relationship between the organic and mineral components of the shells, with carotenoid distribution and carbonate ion substitution in the calcium carbonate lattice following similar growth patterns. These findings highlight the potential of Raman spectroscopy for studying biomineralization processes and the environmental records preserved in marine mollusk shells.